<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Document</title>
    <style>
        *{
            margin: 0;
            height: 0;
        }
        html,body{
            width: 100%;
            height: 100%;
        }
        body{
            background-color: pink;
            display: flex;
            flex-direction: row;
            align-items: center;
            justify-content: center;
        }
    .heart{
        width: 200px;
        height: 200px;
        background-color: red;
        position: relative;
        transform: rotate(45deg);
        animation: heartbit 1s alternate infinite;
    }
    .heart::before{
        content: "";
        width: 200px;
        height: 100px;
        background-color: red;
        position: absolute;
        left: 0;
        top: -99px;
        border-radius: 100px 100px 0 0;
    }
.heart::after{
    content: "";
        width: 100px;
        height: 200px;
        background-color: red;
        position: absolute;
        left: -99px;
        top: 0;
        border-radius: 100px 0 0 100px ;
}
@keyframes heartbit {
    0%{
        transform: rotate(45deg) scale(0.6);
    }
    /* 25%{
        transform: rotate(45deg) scale(0.8);
    }
    50%{
        transform: rotate(45deg) scale(1.0);
    }
    75%{
        transform: rotate(45deg) scale(1.2);
    } */
    100%{
        transform: rotate(45deg) scale(1.4);
    }
}
    </style>
</head>
<body>

    <div class="heart"></div>

</body>
</html>
 